Oil-in-water organosiloxane emulsion compositions are used in a broad range of fields as an ingredient in, for example, fiber-treatment agents, release agents, cosmetics, polishes, and so forth. Particularly in the case of cosmetic applications, large particle size oil-in-water organosiloxane emulsion compositions have been disclosed based on the expectation of a strong conditioning effect when incorporated into hair cosmetics, for example, shampoos, rinses, and so forth.
For example, Patent Reference 1 (JP 11-148011 A) discloses a cationic emulsion composition that has an average particle size of 1 to 20 microns and that comprises organosiloxane, cationic surfactant, polyhydric alcohol, and water. Patent Reference 2 (JP 07-188557 A) discloses an anionic emulsion composition that has an average particle size of 3 to 100 microns and that comprises organosiloxane, anionic surfactant, and water.
While these emulsion compositions do encompass emulsion compositions that are used as an ingredient in, for example, hair cosmetics, an ionic surfactant is an essential component of these emulsion compositions, and, depending on the ionicity of the base used for the hair cosmetic (e.g., shampoo, rinse, etc.), the stability after the incorporation of such emulsion compositions can be drastically impaired.
Thus, when an anionic emulsion composition is blended into a hair cosmetic base comprising a cationic surfactant, the charge on the surfactant in the base cancels the charge on the surfactant in the emulsion composition and the surfactancy is reduced, which can cause the emulsion in the hair cosmetic to break. In addition, the incorporation of this anionic emulsion composition into a hair cosmetic comprising a cationic surfactant can result in a reduction in the viscosity of the hair cosmetic composition, separation of the constituent components with elapsed time, a decline in the cleaning power of the hair cosmetic, and a timewise deterioration in the tactile sensation. The same is true for the incorporation of a cationic emulsion composition into a hair cosmetic base comprising an anionic surfactant.
Due to this, there has been demand for a hair cosmetic ingredient comprising a nonionic oil-in-water organosiloxane emulsion composition that substantially does not contain ionic emulsifying agent and that may be unproblematically incorporated even into hair cosmetics that have an ionic surfactant—of any ionicity—as their base. There has been particularly strong demand for oil-in-water organosiloxane emulsion composition having a large particle size that substantially does not contain ionic emulsifying agent and that provides an excellent improvement in the tactile sensation of hair cosmetics.
Moreover, within the sphere of the heretofore known nonionic oil-in-water organosiloxane emulsion compositions, a problem in the particular case of the production of large particle size oil-in-water organosiloxane emulsion compositions has been the appearance of separation in such an emulsion composition with elapsed time, and there has been strong demand for improvements in the long-term storage stability sufficient for use as a cosmetic ingredient.    [Patent Reference 1] JP 11-148011 A    [Patent Reference 2] JP 07-188557 A